Valve device, fluid control system, fluid control method, semiconductor manufacturing system, and semiconductor manufacturing method

ABSTRACT

A valve device includes: a valve body that forms a first flow path and a second flow path; an inner disc that includes an inner annular part disposed around an opening of the first flow path, an outer annular part disposed on an outer peripheral side of the inner annular part, and a connecting part that includes a plurality of openings that communicates with the second flow path and that connects the inner annular part and the outer annular part; a valve seat disposed on the inner annular part; and a diaphragm that, at a peripheral edge part of the diaphragm, comes into contact with the outer annular part and makes the first flow path and the second flow path continuous and discontinuous by moving between an open position of non-contact and a closed position of contact with the valve seat.

TECHNICAL FIELD

The present invention relates to a valve device, a fluid control system,a fluid control method, a semiconductor manufacturing system, and asemiconductor manufacturing method.

BACKGROUND

In a semiconductor manufacturing process, for example, a valve device isused that controls a supply of various process gases to a chamber of asemiconductor manufacturing system.

In Patent Document 1, there is disclosed a diaphragm valve thatcomprises a retainer holding a seat holder detachably disposed on a bodyand holding a seat, and a retainer detachably attached to a diaphragmholding member while holding the seat holder. The retainer has asubstantially cylindrical shape and includes an inward flange part thatreceives an outer peripheral edge part of the seat holder.

In Patent Document 2, there is disclosed another diaphragm valve. Arecess of a main body of this diaphragm valve includes a large diameterpart close to the opening and a small diameter part aligned below thelarge diameter part via a step part. A flow path forming disc is fittedto the recess. The flow path forming disc includes a large diametercylindrical part fitted to the large diameter part of the recess, acoupling part received by the step part of the recess, and a smalldiameter cylindrical part including an outer diameter smaller than aninner diameter of the small diameter part of the recess and a lower endreceived by a bottom surface of the recess. A plurality of through holescommunicating an outer annular space of the small diameter cylindricalpart and an inner annular space of the large diameter cylindrical partis formed in the coupling part of the flow path forming disc. A fluidinflow passage communicates with a lower end of the small diametercylindrical part of the flow path forming disc, and a fluid outflowpassage communicates with the outer annular space of the small diametercylindrical part.

-   Patent Document 1: JP 2013-117269 A-   Patent Document 2: JP 2005-172026 A

For example, in an atomic layer deposition (ALD), a process gas used ina treatment process that deposits a film on a substrate needs to besupplied in a stable manner at a higher flow rate.

In light of the circumstances mentioned above, one or more embodimentsof the present invention provide a valve device capable of controlling ahigh flow rate in a more stable manner, a fluid control system that usesthis valve device, a fluid control method, a semiconductor manufacturingsystem, and a semiconductor manufacturing method.

SUMMARY

A valve device according to one or more embodiments includes: a valvebody that forms a first flow path and a second flow path; an inner discthat includes an inner annular part disposed around an opening of thefirst flow path, an outer annular part disposed on an outer peripheralside of the inner annular part, and a connecting part provided with aplurality of openings communicating with the second flow path andconnecting the inner annular part and the outer annular part; a valveseat disposed on the inner annular part; a diaphragm that, at aperipheral edge part thereof, comes into contact with the outer annularpart, and makes the first flow path and the second flow path continuousand discontinuous by moving between an open position of non-contact anda closed position of contact with the valve seat; and a pressing adapterthat sandwiches the peripheral edge part of the diaphragm with the outerannular part, and comes into contact with the peripheral edge part. Anoutermost position of a diaphragm contact surface of the outer annularpart that comes into contact with the diaphragm is on an outer side ofan innermost position of a body contact surface of the outer annularpart that comes into contact with a surface of the valve body orthogonalto an axial direction.

Further, in the valve device according to one or more embodiments, theoutermost position of the diaphragm contact surface may be on an outerside of an outermost position of the body contact surface.

Further, in the valve device according to one or more embodiments, thediaphragm may be a dome type in which a curve forming a curved surfacein the open position has no inflection point.

Further, the valve device according to one or more embodiments mayfurther include a disc seal disposed between the inner annular part andthe valve body, and held by a disc seal recessed part formed on thevalve body side of the inner annular part.

Further, in the valve device according to one or more embodiments, theinner annular part may include a valve seat recessed part formed on thediaphragm side, and the valve seat may be held by the valve seatrecessed part and be made of a same material and have a same shape asthe disc seal.

Further, in the valve device according to one or more embodiments, theinner annular part may have a tubular shape longer than the outerannular part in a direction of extension of a center line, an inner sideof the inner annular part communicates with the first flow path, and anouter side of the inner annular part communicates with the second flowpath.

A valve device according to one or more embodiments includes: a valvebody that forms a first flow path and a second flow path; an inner discthat includes an inner annular part disposed around an opening of thefirst flow path, an outer annular part disposed on an outer peripheralside of the inner annular part, and a connecting part provided with aplurality of openings communicating with the second flow path andconnecting the inner annular part and the outer annular part; a valveseat disposed on the inner annular part; a diaphragm that, at aperipheral edge part thereof, comes into contact with the outer annularpart, and makes the first flow path and the second flow path continuousand discontinuous by moving between an open position of non-contact anda closed position of contact with the valve seat; and a pressing adapterthat sandwiches the peripheral edge part of the diaphragm with the outerannular part, and comes into contact with the peripheral edge part. Aradius of a circle formed by an outer edge of, among a surface on thediaphragm side and a surface on the valve body side formed on the outerannular part and opposite from each other, the surface on the diaphragmside is greater than a radius of a circle formed by an inner edge of thesurface on the valve body side.

Further, in the valve device according to one or more embodiments, aradius of a circle formed by an outer edge of, among a surface on thediaphragm side and a surface on the valve body side, the surface on thediaphragm side may be greater than a radius of a circle formed by anouter edge of the surface of the valve body side.

A fluid control system in one or more embodiments is a fluid controlsystem including a plurality of fluid devices arranged from an upstreamside toward a downstream side and including any one of the valve devicesmentioned above.

A flow control method according to one or more embodiments is a methodfor adjusting a flow rate of a fluid using any one of the valve devicesmentioned above.

A semiconductor manufacturing system according to one or moreembodiments includes any one of the valve devices mentioned above forcontrol of the process gas in a manufacturing process of a semiconductordevice that requires a treatment process by the process gas in a sealedchamber.

A semiconductor manufacturing method according to one or moreembodiments includes a step of using any one of the valve devicesmentioned above for flow control of the process gas in a manufacturingprocess of a semiconductor device that requires a treatment process bythe process gas in a sealed chamber.

According to the present invention, it is possible to control a highflow rate in a more stable manner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view illustrating a configuration of a valvedevice according to one or more embodiments of the present invention.

FIG. 2 is a sectional view illustrating a closed state of the valvedevice in FIG. 1.

FIG. 3 is a top view of an inner disc.

FIG. 4 is a sectional view of the inner disc along line IV-IV in FIG. 3.

FIG. 5 is a partial sectional view illustrating a case where a groovehousing a disc seal is formed in an arranged position of the inner discin a valve body.

FIG. 6 is an enlarged sectional view for explaining an outer annularpart.

FIG. 7 is an outline drawing for explaining how the force is appliedfrom the diaphragm in the inner disc.

FIG. 8 is an outline drawing for explaining how the force is appliedfrom the diaphragm in the inner disc.

FIG. 9 is a partial sectional view illustrating another valve device.

FIG. 10 is an enlarged sectional view for explaining the outer annularpart of a hat-type diaphragm.

FIG. 11 is a schematic diagram illustrating an example of applying thevalve device according to one or more embodiments of the presentinvention to a semiconductor manufacturing process.

FIG. 12 is a perspective view illustrating an example of a fluid controlsystem that uses the valve device according to one or more embodiments.

DETAILED DESCRIPTION

Embodiments of this disclosure are described below with reference to thedrawings. In the descriptions, the same elements are denoted using thesame reference signs, and duplicate descriptions are omitted asappropriate.

First, an example of a fluid control system in which the presentinvention is applied will be described with reference to FIG. 12.

In the fluid control system illustrated in FIG. 12, there is provided abase plate BS made of metal, arranged in width directions W1, W2, andextending in longitudinal directions G1, G2. It should be noted that W1,W2, G1, and G2 denote front side, rear side, upstream side, anddownstream side directions, respectively. In the base plate BS, variousfluid devices 991A to 991E are installed via a plurality of flow pathblocks 992, and flow paths (not illustrated) through which a fluid flowsfrom the upstream side G1 toward the downstream side G2 are formed bythe plurality of flow path blocks 992.

Here, “fluid device” is a device used in a fluid control system forcontrolling a flow of a fluid, comprising a body defining a fluid flowpath, and provided with at least two flow path ports that open on asurface of this body. Specifically, the fluid device includes the switchvalve (two-way valve) 991A, the regulator 991B, the pressure gauge 991C,the switch valve (three-way valve) 991D, the mass flow controller 991E,and the like, but is not necessarily limited thereto. It should be notedthat an introducing pipe 993 is connected to each of the flow path portson the upstream side of the flow paths (not illustrated) describedabove.

The present invention, while applicable to various valve devices such asthe switch valves 991A, 991D, and the regulator 991B described above,will be described using a case of application to a switch valve as anexample according to one or more embodiments.

FIG. 1 is a sectional view illustrating a configuration of a valvedevice 1 in an open state according to one or more embodiments of thepresent invention. FIG. 2 is a sectional view illustrating a closedstate of the valve device 1 in FIG. 1. As illustrated in FIG. 1, thevalve device 1 comprises a casing 6, a bonnet 5, a valve body 2, aninner disc 3, a valve seat 48, a diaphragm 41, a pressing adapter 43, adiaphragm presser 42, a stem 44, and a coil spring 45. It should benoted that arrows A1, A2 in the drawing indicate upward and downwarddirections, A1 being the upward direction and A2 being the downwarddirection.

The valve body 2 is formed from stainless steel, and includes an uppersurface 2 a and side surfaces 2 b and 2 c opposite from each other. Fromthe upper surface 2 a, a valve chamber 23 having a space in which theinner disc 3 is disposed and a step part 24 opens, and a screw hole 25comprising a thread groove screwed with the bonnet 5 is formed. Further,the valve body 2 forms a first flow path 21 and a second flow path 22.The first flow path 21 is a flow path that opens on the side surface 2 band a bottom surface of the valve chamber 23. The second flow path 22 isa flow path that opens on the side surface 2 c and a side surface of thevalve chamber 23.

The diaphragm 41, at a peripheral edge part thereof, comes into contactwith an outer annular part 31 of the inner disc 3 described later, andmakes the first flow path 21 and the second flow path 22 continuous anddiscontinuous by moving between a closed position of contact and an openposition of non-contact with the valve seat 48. The casing 6incorporates an actuator 8 that drives the diaphragm 41, and is fixed onthe bonnet 5 via a connecting member 65. According to one or moreembodiments, the valve body 2 and the bonnet 5 are screwed into thecasing 6 via the connecting member 65, but may be configured without theconnecting member 65. An operating member 7 moves between a closedposition and an open position in which the diaphragm 41, serving as avalve element, respectively closes and opens the opening of the firstflow path 21. The operating member 7 of the actuator 8 is formed in asubstantially cylindrical shape, held by an inner peripheral surface ofa circular hole 54 of the bonnet 5 and an inner peripheral surface of acircular hole 64 formed inside the casing 6, and moveably supported inthe upward and downward directions A1, A2. An O-ring 91 is disposedbetween inner peripheral surfaces of circular holes 54 and 64 and theoperating member 7, securing airtightness.

In the interior of the bonnet 5, the operating member 7 is coupled withthe stem 44, and the stem 44 moves along with the operating member. Thestem 44, in the interior of the bonnet 5, is pressed by the coil spring45 in the downward direction A2 relative to the bonnet 5, that is, inthe direction in which the diaphragm 41 is moved to the closed position.While the coil spring 45 is used according to one or more embodiments,the present invention is not necessarily limited thereto, and othertypes of elastic members can be used, such as a disc spring or a leafspring. The diaphragm presser 42 that is made of a synthetic resin suchas polyimide and comes into contact with a central upper surface of thediaphragm 41 is mounted on a lower end surface of the stem 44.

In the interior of the casing 6, one or a plurality of bulkheads 82having an annular shape is formed around the operating member 7, and oneor a plurality of pistons 81 is disposed in a cylinder 83 sandwichedbetween an upper surface 5 a of the bonnet 5 and the one or plurality ofbulkheads 82. The O-ring 91 is disposed between the pistons 81 and theinner peripheral surface forming the space in the interior of the casing6, and between the operating member 7 and the piston 81, securingairtightness.

The cylinders 83 and the pistons 81 constitute the actuator 8 that movesthe operating member 7 into the open position against the coil spring45. The actuator 8, for example, increases the area on which pressureacts by using the plurality of pistons 81, making it possible to boostthe force obtained from the operation gas. A space on an upper side ofthe piston 81 of each of the cylinders 83 opens to the atmosphere by aventilation path 62 or the like.

A space on a lower side of the piston 81 of each of the cylinders 83communicates with an operating member flow channel 71 formed in theoperating member 7. The operating member flow channel 71 communicateswith an operation gas supply port 61 connected to the circular hole 64formed on an upper surface 6 a of the casing 6. As a result, theoperation gas supplied from the operation gas supply port 61 is suppliedto the cylinder 83, and the piston 81 is pushed up in the upwarddirection A1. It should be noted that the configurations of the casing6, the actuator 8, the bonnet 5, the stem 44, the diaphragm presser 42,and the coil spring 45 are examples of configurations for an automaticvalve device that controls the opening and closing of the valve elementby compressed air, and other known configurations or the like can beselected as appropriate. Further, these configurations need not beprovided in cases of a manual valve device or the like.

The inner disc 3 is disposed in the valve chamber 23, and opens on thediaphragm 41 side while securing a seal performance of the first flowpath 21 with respect to the second flow path 22. FIG. 3 is a top view ofthe inner disc 3. FIG. 4 is a sectional view of the inner disc 3 alongline IV-IV in FIG. 3. As illustrated in these drawings, the inner disc 3includes an inner annular part 32, the outer annular part 31, and aconnecting part 37. The inner annular part 32 is disposed around theopening of the first flow path 21, and comprises a first opening 33. Theouter annular part 31 has an annular shape concentric with the innerannular part 32. The connecting part 37 has a plurality of secondopenings 34 communicating with the second flow path 22, and connects theinner annular part 32 and the outer annular part 31. It should be notedthat the outer annular part 31 is disposed on the step part 24 of thevalve chamber 23.

According to one or more embodiments, the inner annular part 32 has atubular shape longer than the outer annular part 31 in a direction ofextension of a center line CL, an inner side of the inner annular part32 communicates with the first flow path 21, and an outer side of theinner annular part 32 communicates with the second flow path 22. Withsuch a configuration, it is possible to provide the opening of the firstflow path 21 on the bottom surface of the valve chamber 23 and theopening of the second flow path 22 on the side surface of the valvechamber 23, thereby making it possible to further increase the diametersof the first flow path 21 and the second flow path 22. As a result, theflow rate in the open state can be increased. However, the configurationmay be such that the valve chamber 23 has a shallow depth, and the innerannular part 32 used has about the same length as the outer annular part31.

The valve seat 48 is disposed on the inner annular part 32. Further, thevalve device 1 may further comprise a disc seal 49 disposed between theinner annular part 32 and the valve body 2. The disc seal 49 is held bya disc seal recessed part 36, which is a groove formed on the valve body2 side of the inner annular part 32. Furthermore, the inner annular part32 may include a valve seat recessed part 35, which is a groove formedon the diaphragm 41 side, and the valve seat 48 may be held by the valveseat recessed part 35. The disc seal 49 blocks the area between theinner side and the outer side of the inner annular part 32 on the valvebody 2 side of the inner annular part 32, and secures airtightness.

The valve seat 48 may be fixed by swaging in the valve seat recessedpart 35, or the like. Further, the disc seal 49 may be fixed by swagingin the disc seal recessed part 36, or the like. With the valve seat 48and the disc seal 49 thus fixed to the inner disc 3, it is possible toprevent displacement during assembly and during operation, and furthersimplify the manufacturing process. In particular, with the disc seal 49fixed to the inner disc 3, there is no need to form a groove or the likefor positioning the disc seal 49 to the valve body 2, furthersimplifying the positioning task during assembly as well, and thusmaking it possible to further reduce manufacturing costs and improveyield. Further, as illustrated in the partial sectional view of FIG. 5,the valve body 2 may include a groove M for disposing the disc seal 49.When high-temperature fluid is introduced, a contact area between thefluid and the disc seal 49 is minimized by forming the groove M in thevalve body 2, making it possible to suppress expansion of the disc seal49 caused by heating. Further, the disc seal 49 is housed in the grooveM and a lower end of the inner disc 3 comes into contact with the valvebody 2, separating the inner side and the outer side of the inner disc3, making it possible to accurately define a height of the valve seat48. In addition, even if the disc seal 49 is expanded, a volume of theexpanded disc seal 49 is kept within the groove M, making it possible toprevent the inner disc 3 from rising while securing a seal performance,and stably hold the height of the valve seat 48. Thus, the seal on thevalve body 2 side of the inner disc 3 is made more reliable by the discseal 49, allowing the valve device 1 to control a high flow rate in amore stable manner.

The valve seat 48 and the disc seal 49 may be made of a synthetic resin(such as perfluoroalkoxy alkane (PFA), polyamide (PA), polyimide (PI),or polychlorotrifluoroethylene (PCTFE)). Further, the valve seat 48 maybe made of the same material and have the same shape as the disc seal49. That is, the valve seat 48 and the disc seal 49 may be obtained byattaching the same parts vertically in reverse. As a result, the partscan be made common, making it possible to reduce product costs.

The diaphragm 41 closes the first opening 33 that extends from the firstflow path 21 of the valve body 2 to make the first flow path 21 and thesecond flow path 22 discontinuous, and opens the first opening 33 tomake the first flow path 21 and the second flow path 22 continuous. Thediaphragm 41 is arranged above the valve seat 48, holds an airtightnessof the valve chamber 23, and makes the first flow path 21 and the secondflow path 22 continuous or discontinuous by a central part thereofmoving up and down and being brought into contact with and separatingfrom the valve seat 48. According to one or more embodiments, thediaphragm 41 is obtained by swelling central parts of a thin plate madeof a metal such as a special stainless steel, and a nickel and cobaltalloy thin plate upward, and thus has a spherical shell shape in whichan upwardly convex arc shape is the natural state. The diaphragm 41 isformed in an elastically deformable manner into a spherical shell shapeby a metal such as stainless or a NiCo-based alloy, or a fluorine-basedresin, for example.

The diaphragm 41, at the peripheral edge part thereof, is mounted on theouter annular part 31 of the inner disc 3, and a lower end part of thebonnet 5 inserted into the valve chamber 23 is screwed into the screwhole 25 of the valve body 2, thereby pressing the diaphragm 41 to theouter annular part 31 side of the inner disc 3 via the pressing adapter43 made of a stainless alloy, for example, and sandwiching and fixingthe diaphragm 41 in an airtight state. That is, the diaphragm 41 isfixed by sandwiching a peripheral edge part thereof between the pressingadapter 43 and the outer annular part 31. It should be noted that, asthe diaphragm 41, a diaphragm having another configuration can also beused. Here, the diaphragm 41 may be a dome type in which a curve forminga curved surface has no inflection point in a natural state. “A curveforming a curved surface has no inflection point” refers to, forexample, a curve having no inflection point in a case where there is acurve forming a curved surface of the diaphragm 41 by rotation. “Has noinflection point” is the same meaning as no change in the sign of thecurvature. With the diaphragm 41 thus having a dome type, it is possibleto increase the distance from the valve seat 48 in the open position andmake the flow path larger, making it possible to increase the flow rate.

FIG. 6 is an enlarged sectional view for explaining the outer annularpart 31. Here, the diaphragm 41 is described using the case of theaforementioned dome type. As illustrated in FIG. 6, when the diaphragm41 is a dome type, the diaphragm 41 has an angle θ relative to a surfaceorthogonal to the upward and downward directions A1, A2, even at an edgepart thereof. Thus, the diaphragm 41 comes into contact at a corner partof the outer annular part 31, and a force F is applied to the outerannular part 31 in an oblique inward direction from the diaphragm 41 inthis contact portion. Here, the surface of the outer annular part 31that comes into contact with the diaphragm 41 is a diaphragm contactsurface T1. According to one or more embodiments, an outermost positionPd of the diaphragm contact surface T1 is on an outer side of aninnermost position Pbi of a body contact surface T2 where the outerannular part 31 comes into contact with the step part 24 of the valvebody 2. Here, the terms “outer side” and “inner side” are based on thecenter line CL of the outer annular part 31 and the inner annular part32. Further, the body contact surface T2 is a surface orthogonal to anaxial direction, which is the direction in which the center line CLextends, and is a support surface.

FIG. 7 is an outline drawing for explaining how the force F from thediaphragm 41 is applied when the outermost position Pd of the diaphragmcontact surface T1 is on an inner side of the innermost position Pbi ofthe body contact surface T2. FIG. 8 is an outline drawing for explaininghow the force from the diaphragm 41 is applied when the outermostposition Pd of the diaphragm contact surface T1 is on an outer side ofthe innermost position Pbi of the body contact surface T2. Asillustrated in FIG. 7, when the outermost position Pd of the diaphragmcontact surface T1 is on the inner side of the innermost position Pbi ofthe body contact surface T2, and the force F is applied in the obliqueinward direction from the diaphragm contact surface T1, the force F actsas a bending force so that the central portion of the inner disc 3sinks. Such a force may affect the securing of airtightness by the innerdisc 3 inside the valve device 1, or the durability of the inner disc 3itself.

On the other hand, even when the outermost position Pd of the diaphragmcontact surface T1 is on the outer side of the innermost position Pbi ofthe body contact surface T2 as illustrated in FIG. 6 and the force F isapplied in the oblique inward direction as illustrated in FIG. 8, theouter annular part 31 receives the force between the outer annular part31 and the valve body 2, making it possible to suppress a force thatdeforms the inner disc 3. Here, the outermost position Pd of thediaphragm contact surface T1 may be on an outer side of an outermostposition Pbo of the body contact surface T2. In this case, the outerannular part 31 can receive the force F in a more oblique inwarddirection, making it possible to further suppress deformation of theinner disc 3. Accordingly, with such a configuration, the valve device 1can control a high flow rate in a more stable manner.

Further, back to FIG. 6, with a focus on the cross-sectional shape ofthe outer annular part 31, the cross-sectional shape of the outerannular part 31 includes a surface S1 on the diaphragm side, and asurface S2 on the valve body side, which are surfaces opposite from eachother. A radius Rd of a circle formed by an outer edge of, among thesurface S1 on the diaphragm side and the surface S2 on the valve bodyside, the surface S1 on the diaphragm side is formed greater than aradius Rbi of a circle formed by an inner edge of the surface S2 on thevalve body side. In such a configuration, even when the force F isapplied in the oblique inward direction, the outer annular part 31receives the force between the outer annular part 31 and the valve body2, making it possible to suppress deformation of the inner disc 3.

Here, the radius Rd of a circle formed by an outer edge of, among thesurface S1 on the diaphragm side and the surface S2 on the valve bodyside, the surface S1 on the diaphragm side may be formed greater than aradius Rbo of a circle formed by an outer edge of the surface S2 on thevalve body side. In this case, the outer annular part 31 can receive theforce F in a more oblique inward direction, making it possible tofurther suppress deformation of the inner disc 3. Accordingly, with sucha configuration, the valve device 1 can control a high flow rate in amore stable manner.

FIG. 9 is a partial sectional view illustrating another valve device100. The valve device 100 is an automatic valve device that controls thevalve element by compressed air for high temperatures. In thedescription of FIG. 9, the corresponding sections of the valve device 1in FIGS. 1 and 2 are denoted using the same reference signs, anddescriptions thereof are omitted. In FIG. 9, a diaphragm 101, unlike thecase of FIGS. 1 and 2, is a hat type in which a curve forming a curvedsurface in the open position has an inflection point. In the diaphragm101 on the hat side, a peripheral edge part of the diaphragm 101sandwiched between the outer annular part 31 and the pressing adapter 43is a surface substantially orthogonal to the upward and downwarddirections A1, A2.

FIG. 10 is an enlarged sectional view for explaining the outer annularpart 31 of the hat-type diaphragm 101. As mentioned above, theperipheral edge part of the diaphragm 101 sandwiched between the outerannular part 31 and the pressing adapter 43 extends in a substantiallyorthogonal direction to the upward and downward directions A1, A2. Inthis case as well, as described in FIGS. 7 and 8, when the outermostposition Pd of the diaphragm contact surface T1 is on the inner side ofthe innermost position Pbi of the body contact surface T2, the force Ffrom the diaphragm contact surface T1 acts as a bending force so thatthe central portion of the inner disc 3 sinks. Accordingly, in the sameway as described in FIG. 6, when the outermost position Pd of thediaphragm contact surface T1 is on the outer side of the innermostposition Pbi of the body contact surface T2, deformation of the innerdisc 3 can be suppressed. Further, the outermost position Pd of thediaphragm contact surface T1 in which the outer annular part 31 comesinto contact with the diaphragm 101 may be on an outer side of theoutermost position Pbo of the body contact surface T2 where the outerannular part 31 comes into contact with the valve body 2. In this case,the outer annular part 31 can receive the force F further on the innerside, making it possible to further suppress deformation of the innerdisc 3. Accordingly, with such a configuration, the valve device 100 cancontrol a high flow rate in a more stable manner.

Further, in the same way as in FIG. 6, the radius Rd of the circleformed by the outer edge of, among the surface S1 on the diaphragm sideand the surface S2 on the valve body side, the surface S1 on thediaphragm side may be formed greater than the radius Rbi of the circleformed by the inner edge of the surface S2 on the valve body side. Inthis case as well, the outer annular part 31 receives the force betweenthe outer annular part 31 and the valve body 2, making it possible tosuppress deformation of the inner disc 3. Further, the radius Rd of thecircle formed by the outer edge of, among the surface S1 on thediaphragm side and the surface S2 on the valve body side, the surface S1on the diaphragm side may be formed greater than the radius Rbo of thecircle formed by the outer edge of the surface S2 on the valve bodyside. In this case, the outer annular part 31 can receive the force Ffurther on the inner side, making it possible to further suppressdeformation of the inner disc 3. Accordingly, with such a configuration,the valve device 100 can control a high flow rate in a more stablemanner.

Next, an application example of the valve device 1 described above willbe described with reference to FIG. 11.

A semiconductor manufacturing system 980 illustrated in FIG. 11 is asystem for executing a semiconductor manufacturing process by the ALDmethod, with 981 denoting a process gas supply source, 982 denoting agas box, 983 denoting a tank, 984 denoting a control unit, 985 denotinga processing chamber, and 986 denoting an exhaust pump.

In the semiconductor manufacturing process based on the ALD method, theflow rate of the process gas needs to be precisely adjusted and securedto a certain extent by increasing a size of a diameter of the substrate.

The gas box 982 is an integrated gas system (a fluid control system) inwhich various fluid control devices, such as a switch valve, aregulator, and a mass flow controller, are integrated and housed in abox to supply an accurately measured process gas to the processingchamber 985.

The tank 983 functions as a buffer for temporarily storing the processgas supplied from the gas box 982.

The control unit 984 controls flow adjustment by controlling the supplyof the operation gas to the valve device 1.

The processing chamber 985 provides a sealed treatment space for forminga film on the substrate by the ALD method.

The exhaust pump 986 draws a vacuum inside the processing chamber 985.

According to such a system configuration as described above, initialadjustment of the process gas is possible as long as a directive forflow adjustment is sent from the control unit 984 to the valve device 1.

It should be noted that the present invention is not limited to theaforementioned embodiments. Those skilled in the art can make variousadditions and modifications within the scope of the present invention.For example, while a case where the valve device 1 is used in asemiconductor manufacturing process based on the ALD method isillustrated in the above-described application example, the presentinvention is not necessarily limited thereto, and can be applied tovarious targets that require precise flow adjustment, such as an atomiclayer etching (ALE) method, for example.

While a piston built into a cylinder activated by gas pressure is usedas the actuator in the above-described embodiments, the presentinvention is not necessarily limited thereto, and optimal actuators canbe variously selected in accordance with the control target.

While, in the configuration of the above-described embodiments, thevalve device 1 is disposed outside the gas box 982 serving as a fluidcontrol system, the valve device 1 of the above-described embodimentscan also be included in a fluid control system that integrates andhouses various fluid devices such as a switch valve, a regulator, and amass flow controller in a box.

While the valve device is mounted on the plurality of flow path blocks992 as a fluid control system illustrated in the above-describedembodiments, in addition to the divided-type flow path block 992, thevalve device of the present invention can also be applied to anintegrated flow path block and a base plate.

REFERENCE NUMERALS LIST

-   1 Valve device-   2 Valve body-   2 a Upper surface-   2 b Side surface-   2 c Side surface-   3 Inner disc-   5 Bonnet-   5 a Upper surface-   6 Casing-   6 a Upper surface-   7 Operating member-   8 Actuator-   21 First flow path-   22 Second flow path-   23 Valve chamber-   24 Step part-   25 Screw hole-   31 Outer annular part-   32 Inner annular part-   33 First opening-   34 Second opening-   35 Valve seat recessed part-   36 Disc seal recessed part-   37 Connecting part-   41 Diaphragm-   42 Diaphragm presser-   43 Pressing adapter-   44 Stem-   45 Coil spring-   48 Valve seat-   49 Disc seal-   54 Circular hole-   61 Operation gas supply port-   62 Ventilation path-   64 Circular hole-   65 Connecting member-   71 Operating member flow channel-   81 Piston-   82 Bulkhead-   83 Cylinder-   91 O-ring-   100 Valve device-   101 Diaphragm-   980 Semiconductor manufacturing system-   981 Process gas supply source-   982 Gas box-   983 Tank-   984 Control unit-   985 Processing chamber-   986 Exhaust pump-   991A Switch valve-   991B Regulator-   991C Pressure gauge-   991D Switch valve-   991E Mass flow controller-   992 Flow path block-   993 Introducing pipe-   A1 Upward direction-   A2 Downward direction-   BS Base plate-   CL Center line-   F Force-   G1 Longitudinal direction (upstream side)-   G2 Longitudinal direction (downstream side)-   M Groove-   Rbi, Rbo, Rd Radius-   S1 Surface on diaphragm side-   S2 Surface on valve body side-   T1 Diaphragm contact surface-   T2 Body contact surface-   W1, W2 Width direction-   θ Angle

Although the disclosure has been described with respect to only alimited number of embodiments, those skilled in the art, having benefitof this disclosure, will appreciate that various other embodiments maybe devised without departing from the scope of the present invention.Accordingly, the scope of the invention should be limited only by theattached claims.

1. A valve device comprising: a valve body that forms a first flow path and a second flow path; an inner disc that includes: an inner annular part disposed around an opening of the first flow path; an outer annular part disposed on an outer peripheral side of the inner annular part; and a connecting part that: comprises a plurality of openings that communicates with the second flow path, and connects the inner annular part and the outer annular part; a valve seat disposed on the inner annular part; a diaphragm that: comprises a peripheral edge part that contacts the outer annular part, and moves between an open position and a closed position, wherein in the open position, the diaphragm does not contact the valve seat, and the first flow path and the second flow path are continuous, and in the closed position, the diaphragm contacts the valve seat, and the first flow and the second flow path are discontinuous; and a pressing adapter that sandwiches the peripheral edge part with the outer annular part and that contacts the peripheral edge part, wherein the outer annular part comprises: a diaphragm contact surface that contacts the diaphragm; and a body contact surface that contacts a surface of the valve body, wherein an outermost position of the diaphragm contact surface is on an outer side of an innermost position of the body contact surface.
 2. The valve device according to claim 1, wherein the outermost position of the diaphragm contact surface is on an outer side of an outermost position of the body contact surface.
 3. The valve device according to claim 1, wherein the diaphragm is dome-shaped with a curved surface that has no inflection point in the open position.
 4. The valve device according to claim 1, further comprising: a disc seal that is disposed between the inner annular part and the valve body and that is held in a disc seal groove, wherein the disc seal groove is disposed on a valve body side of the inner annular part.
 5. The valve device according to claim 4, wherein: the inner annular part includes a valve seat groove disposed on a diaphragm side of the inner annular part and the valve seat is: held in the valve seat groove, made of a same material as the disc seal, and a same shape as the disc seal.
 6. The valve device according to claim 1, wherein the inner annular part: has a tubular shape longer than the outer annular part in a direction of extension of a center line of the inner disc, and communicates: with the first flow path on an inner side of the inner annular part, and with the second flow path on an outer side of the inner annular part.
 7. A valve device comprising: a valve body that forms a first flow path and a second flow path; an inner disc that includes: an inner annular part disposed around an opening of the first flow path; an outer annular part disposed on an outer peripheral side of the inner annular part; and a connecting part that: comprises a plurality of openings that communicates with the second flow path, and connects the inner annular part and the outer annular part; a valve seat disposed on the inner annular part; a diaphragm that: comprises a peripheral edge part that contacts the outer annular part, and moves between an open position and a closed position, wherein in the open position, the diaphragm does not contact the valve seat, and the first flow path and the second flow path are continuous, and in the closed position, the diaphragm contacts the valve seat, and the first flow and the second flow path are discontinuous; and a pressing adapter that sandwiches the peripheral edge part with the outer annular part and that contacts the peripheral edge part, wherein the outer annular part comprises: a diaphragm side surface; and a valve body side surface that is opposite the diaphragm side surface, wherein a radius of a circle formed by an outer edge of the diaphragm side surface is greater than a radius of a circle formed by an inner edge of the valve body side surface.
 8. The valve device according to claim 7, wherein a radius of a circle formed by an outer edge of the diaphragm side surface is greater than a radius of a circle formed by an outer edge of the valve body side surface.
 9. A fluid control system comprising a plurality of fluid devices that is arranged from an upstream side toward a downstream side and that includes the valve device of claim
 1. 10. A flow control method for adjusting a flow rate of a fluid using the valve device of claim
 1. 11. A semiconductor manufacturing system comprising the valve device of claim 1 for control of a process gas in a manufacturing process of a semiconductor device that requires a treatment process by the process gas in a sealed chamber.
 12. A semiconductor manufacturing method comprising a step of using the valve device of claim 1 for flow control of a process gas in a manufacturing process of a semiconductor device that requires a treatment process by the process gas in a sealed chamber.
 13. A fluid control system comprising a plurality of fluid devices that is arranged from an upstream side toward a downstream side and that includes the valve device of claim
 7. 14. A flow control method for adjusting a flow rate of a fluid using the valve device of claim
 7. 15. A semiconductor manufacturing system comprising the valve device of claim 7 for control of a process gas in a manufacturing process of a semiconductor device that requires a treatment process by the process gas in a sealed chamber.
 16. A semiconductor manufacturing method comprising a step of using the valve device of claim 7 for flow control of a process gas in a manufacturing process of a semiconductor device that requires a treatment process by the process gas in a sealed chamber. 